Book shelves



FIG. 1 is a top plan view of a book shelves;

FIG. 2 is a back view thereof;

FIG. 3 is a left view thereof;

FIG. 4 is a right view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a perspective view thereof; and,

FIG. 8 is a partially collapsed perspective view thereof.

The broken lines showing of portions of the book shelves form no part of the claimed design. 

CLAIM The ornamental design for book shelves, as shown and described. 